Already operating robots on Mars may be inadequate for finding signs of life, according to new research.
About half a century ago, when NASA deployed the twin Viking orbiters to Mars, scientists learned that the Red Planet had liquid water on its surface between three and four billion years ago. Subsequent missions confirmed similar discoveries, indicating that life may have been there in the past and may exist there now, as water is necessary for all known forms of life on Earth.
Unfortunately, neither of NASA's Viking landers found any definite evidence of organic compounds in Martian soil. There are very faint signs of basic organic compounds in old Martian lakebeds and river deltas, even according to the most cutting-edge equipment on NASA's later Curiosity and Perseverance rovers. Yet experts have highlighted that these are not irrefutable proof of life; they may have been produced by geological processes.
Exploration and Evidence for Life There is still no way to know if the failure of the search for Martian life, either in the past or the present, is due to the fact that Mars has always been lifeless or because the probes sent there are not sensitive enough to detect any life there. Scientific tools now on Mars or planned for future missions were tested with ultra-sensitive laboratory gear in an effort to shed light on this riddle.
Scientists studied samples from Red Stone, a dried-up river delta in Chile's Atacama Desert, the driest and oldest desert on Earth. The deposits, which are thought to have developed in very dry circumstances between 100 and 160 million years ago, have striking similarities to the Jezero Crater on Mars, the location of an ongoing exploration by the Perseverance.
Red Stone is subject to consistent fog, which provides a reliable source of water for the bacteria that have established themselves there. Modern laboratory methods confirmed the presence of biochemicals from both extinct and active microbes. Half of the bacteria' DNA sequences found at Red Stone were from the "dark microbiome," which scientists have not yet adequately defined.
Based on these results, it appears that it will be extremely challenging, if not impossible, for Mars rovers to identify the trace amounts of organic materials that are thought to be present on the Red Planet today, assuming that microorganisms formerly thrived there.
The Mars Sample Return Mission will now include two helicopters instead of the "fetch" rover.
Scientists hope that by bringing Martian samples back to Earth for testing using cutting-edge technology, they can finally determine once and for all if life ever existed on the Red Planet. By the way, NASA and the European Space Agency plan to accomplish just that, bringing material gathered by Perseverance back to Earth as early as 2033.
